A graphical user interface (GUI) allows a number of graphical representations of operating system objects to be rendered on a display screen at the same time. The graphical representations of system objects, e.g., controls and indicators, can be displayed in the GUI according to the needs of a user. Examples of GUI indicators include alerts, windows, and icons representing files and/or hardware. Examples of GUI controls include icons representing applications and operating system functions, taskbars, menus, virtual buttons, and a keyboard representation. In general, the GUI controls provide mechanisms for accessing and activating, or both, the system objects corresponding to the displayed representations.
The graphical representations of operating system objects, or simply the GUI elements, are typically presented in the GUI in a manner that is conducive to a pleasant user experience. Esthetic aspects of the GUI may contribute to such pleasant user experience. An esthetic aspect of some GUIs involves rendering the GUI elements within respective borders with sharp corners, such that adjacent straight sides of each of the borders meet at one point. In this case, a GUI element rendered in these GUIs has a continuous border with discontinuous slope at the corners. The border slope is determined as a first derivative of a geometrical function that represents the border.
Another esthetic aspect of other GUIs involves rendering the GUI elements within respective borders that have rounded corners, such that the adjacent straight sides of each of the borders are joined together through an elliptical arc, e.g., a circular arc. In this case, both the border and its slope are continuous for a GUI element rendered in the latter GUIs.